This invention relates to an apparatus for attaching a tire component member to a toroidal green case.
In producing radial tires, it is common practice to attach a tire component member to a green case to form a green tire. In more detail, after a green case formed in a first forming unit has been toroidally expanded in a second forming unit, a tire component member such as a belt, tread band or the like is fitted on and attached to the green case to form a green tire.
There have been various apparatus for attaching a tire component member to a toroidal green case, as disclosed e.g. in U.S. Pat. No. 3,819,449. This disclosed apparatus includes a first roller adapted to be brought into contact with a center portion of a green case and rotatable about an axis in parallel with a rotational axis of the green case, and plurality of pairs of second rollers arranged in symmetry on axially outer sides of the first roller and rotatable about axes in parallel with the axis of the first roller. The apparatus further includes a plurality of moving means for individually moving the first and second rollers toward and away from the green case.
In attaching a tire component member to a green case with such a disclosed apparatus, at the outset, the first roller is advanced toward the green case by means of the moving means and the axially center portion of the tire component member is attached to the green case. Thereafter, the pairs of the second rollers are advanced progressively in the order of those nearer to the first roller toward the green case by means of the moving means. The tire component member is then attached to the green case successively from the axially inner side to the axially outer side with the aid of the advanced second rollers.
With such an attaching apparatus, however, there are clearances between the adjacent rollers, which cause air pockets between the green case and the tire component member at locations corresponding to the clearances, or nonuniform or locally weak attaching strength therebetween. Moreover, outer circumferences of the second rollers are adapted to be equally in contact with the tire component member at any axial position of the outer circumference, notwithstanding different circumferential lengths of the second rollers at the axial positions owing to their frustoconical shapes. Consequently, there is a tendency for the second rollers to slip on the tire component member in circumferential directions in the attaching operation, with resultant scratches or scores on the surface of the tire component member. Furthermore, the prior art apparatus requires a number of the rolls and moving means making the apparatus complicated in construction and very expensive.